[NCLUG] Debian wireless broken

[jcrout at softhome.net]

It sounds like everything works except for the WLAN. :-) I mean, you
are able to load the module for the wifi nic and from what you can
see, it ought to be working.  The wrapper scripts may not fiddle with
certain files.

As root, run:

find /proc /sys /dev -type f -name SSID -o -name ESSID

I don't remember whether the files of interest are in /proc /dev/
or /sys.   But the directory where you find the file "SSID" or
"ESSID" will contain several files.  The path will contain a dir
called .../../net and also have a dir that tells the kernel it belongs
to the wifi driver.  (The relationship may be via a has of sorts).

These file are key, nevertheless.  They are parameters that need to
match the AP in-use.  When I was running wifi from RH 8 and Debian
etch, the way to get the wlan up was to set these files using:

	# echo "data in here" > /one-of-those-dirs/.../net/airo/ESSID"

or something to this effect.  There would be a few files that need to
be set, only some of which may be configurable from
/etc/network/interfaces.  Parameters that may be required are the
network ID, the encryption key, and the AP name.  Maybe the mode but
I'd assume it to be correct before fiddling with it.

Hope you'll let me know how it goes.
--
JohnC




On Sat, 5 Mar 2011 10:33:44 -0700
Chad Perrin <perrin at apotheon.com> wrote:

> O Wise and Mysterious Linux Experts, I humbly beg your aid.
> 
> ## Conditions
> 
> I have installed Debian Squeeze/Stable on a ThinkPad T510.  I then
> changed /etc/apt/sources.list to "testing" rather than "squeeze" when
> I remembered that Stable sucks for daily laptop use.
> 
>     03:00.0 Network controller: Intel Corporation Centrino Wireless-N
> 1000 Subsystem: Intel Corporation Centrino Wireless-N 1000 BGN
>         Flags: bus master, fast devsel, latency 0, IRQ 34
>         Memory at f2400000 (64-bit, non-prefetchable) [size=8K]
>         Capabilities: <access denied>
>         Kernel driver in use: iwlagn
> 
> ## What Works
> 
> I have edited the /etc/network/interfaces file to contain stuff that,
> so far as I know, should be appropriate for my networking needs:
> 
>     auto lo
>     iface lo inet loopback
> 
>     auto wlan0
> 
>     iface wlan0 inet dhcp
>       wpa-ssid <SSID>
>       wpa-psk <KEY>
> 
> When I do this, it connects (no problems):
> 
>     /etc/init.d/networking [re]start
> 
> . . . where [re] indicates that I either use start or restart,
> depending on circumstances.
> 
> ## What Doesn't Work
> 
> If I change the iface wlan0 stanza to the following, and try to
> connect to an open network (at, for instance, Panera), it doesn't
> work:
> 
>     iface wlan0 inet dhcp
> 
> I have also tried variants that the Interwebs tell me should allow the
> networking script to dynamically connect me to what's available.  I
> have also tried using GUI tools like NetworkManager and wicd.  I have
> also tried pushing functionality to wpa_supplicant.  I have tried just
> bringing up the wlan0 interface with ifconfig and manually running
> dhclient as well.  The end result is always one of two things:
> 
> 1. I can connect at home just fine, but I cannot connect to open
> wireless access points that do not use encryption.
> 
> 2. I can't connect to anything (as in the case of trying to use
> wpa_supplicant configuration -- how screwed up is that?).
> 
> ## What do I mean by "cannot connect"?
> 
> I'll use Panera as my example.
> 
> I am perfectly able to detect the AP at Panera (for instance) using
> the iwlist command.  I can set the SSID association for wlan0 to
> PANERA.  I cannot get iwconfig to show an AP MAC address association
> -- it just keeps telling me it isn't associated.  Whether I preset
> the SSID or not, and whether I try to preset the AP association or
> not, the results are the same when I try to establish a connection.
> 
> It will go through the process of requesting an IP address, then
> inform me it did not get an IP address assignment from any DHCP
> server, and the DHCP client will "sleep".
> 
> ## Other Details of What I've Tried
> 
> I have also tried installing dhcpd, because of documentation I found
> on the Intertubes suggesting that wicd sometimes works with dhcpd but
> not dhclient -- but wicd will not even recognize the existence of a
> DHCP client other than dhclient.
> 
> When screwing around with NetworkManager, I have come to the
> conclusion that if it does not automagically work when installed, it
> will never work, since trying to configure it is an exercise akin to
> wandering around Willy Wonka's chocolate factory while ODing on LSD.
> 
> When trying to get wicd to work, I have tried both doing as
> recommended by the Google, to borrow a phrase from McCain:
> 
>     configuring /etc/network/interfaces to contain no configuration
> data for any interface except lo
> 
> . . . and half a dozen variations on not following wicd related
> advice, such as configuring a bunch of stuff
> in /etc/network/interfaces, just in case the wicd information I found
> was out of date and counterproductive somehow.
> 
> ## My Plea
> 
> Help . . . ?  What (other than using Debian) am I doing wrong?
> 


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